Magnetic sensors enabled by MEMS and SOI technologies

The size and power reduction of magnetic sensors is attractive for portzble applications. Hall effect, Anisotropic MagnetoResistance and Giant Magnetoresistance sensors have a limited bandwidth, a power in the mW range and require integrating magnetic materials. In this paper, we will show that MEMS and Silicon-on-Insulator are key technologies for the co-integration of magnetic sensing with dedicated CMOS circuit interfaces operating in the µm range. We will discuss and illustrate different strategies for the measurement of magnetic fields, i.e. split-drain thin-film SOI transistors, microcoil indusctors with low power CMOS interface, out-of-plane MEMS and SOIMUMPs devices based on Lorentz's force actuation and piezoresistive or capacitive detection